PATHOGENS AND DISEASE EXPERIENCES IN THE AQUACULTURE OF THE YUCATAN PENINSULA, MEXICO

México´s current aquaculture growth is 17%, an indicator above many other countries developing aquaculture. Main commodities are shrimp and tilapia, although marine finfish aquaculture has been developing since the 90´s resulting in commercial aquaculture venues in the Pacific side. Some freshwater species like basa and trout are cultured in northern and center states while tilapia is cultured all over the country (32 states).  In the Yucatan peninsula tilapia is the most important cultured organism, followed by shrimp and marine finfish in the Gulf of Mexico waters. Still, a common problem facing all aquaculture ventures are pathogens and disease which at some points have caused disastrous impacts; in 2013 a red drum farm off-the coast of Campeche lost 80% of their production due to an undiagnosed outbreak of nocardiosis (Figs. 1&2). During mid 2000´s shrimp farms in Yucatan experienced the effects of ill-combined infections of Taura, white-spot disease and necrotising hepatopancreatitis which depleted the still incipient crustacean farming in the area. For over ten years there was no operative shrimp farm establishments in the whole peninsula.

Streptococcosis is detected with relative frequency y tilapia culture in the area, although no final identification has been issued by any government or dedicated lab. The id of the streptococcus strains is still to be determined. Another common finding are monogenoids parasites; at least 12 different species has been discerned, all of them of African origin. Two of them are very common, and although they seem not to be the cause of direct mortalities, the negative effects of these parasites on the condition factor and biomass loss in cultured tilapia in Yucatan has been recently issued by one of the authors (Figs. 3, 4, 5 & 6).

Mexico possesses laboratories with the standard and advanced tests for the detection of OIE-listed diseases. However, major losses in aquaculture is being caused by non-listed pathogens. Another major conceivable problem is the scarce amount of fish pathology professionals, which increase the vulnerability of aquaculture in the area. Although most curricula for veterinary studies include aquaculture teaching nowadays, pathology as a subject with sound microbiology knowledge needs to be reinforced. If the subject is not deal with proper attention, diseases will remain as the main deterrent of aquaculture sustainability.